[FIXED] Apache POI accessing tables in a XWPFDocument returns only first table

Issue

I'm trying to put every single row from JTable (xlTab, 3 columns) in its own page in XWPFDocument (If rows=10, then pages=10, one row in each page). I have an external template .DOCX file ready and this action will be performed on the document itself. The code is:

File file = JFileChooser1.getSelectedFile();
XWPFDocument order=new XWPFDocument(new FileInputStream(file));
CTBody page=order.getDocument().getBody();
                
XWPFTable table;

for(int x=0;x<xlTab.getRowCount();x++){
    table=order.getTableArray(x);
    System.out.println("Tables present: "+table.toString());
    for(int col=0;col<3;col++){
        table.getRow(0).getCell(col).setText(xlTab.getColumnName(col)+":\n"+xlTab.getValueAt(x,col));
    }
    order.getDocument().AddNewBody().set(page);
}

The error I'm getting is:

Tables present: org.apache.poi.xwpf.usermodel.XWPFTable@3c1e93f9
Exception in thread "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Index 1 out of bounds for length 1

Why does table contain only one Table?

Edit: I'm using Java 18, and the above code is executed on a button click (for nitpickers).

Solution

Creating table through CTTbl resolves this issue:

JFileChooser fc=new JFileChooser();
XWPFDocument template=new XWPFDocument(new FileInputStream(file));    //This is the template file
XWPFDocument intermediate=new XWPFDocument();    //all the changes will be done in this file. Directly modifying template will throw ConcurrentModificationException

CTTbl tbl=CTTbl.Factory.newInstance();
tbl.set(template.getTables().get(0).getCTTbl());    //template contains only one table.
int pos=0;

for(int i=0;i<xlTab.getRowCount();i++){
    for(IBodyElement ele:template.getBodyElements()){
        switch(ele.getElementType()){
            case PARAGRAPH -> {
                intermediate.createParagraph();
                intermediate.setParagraph((XWPFParagraph)ele,pos++);
            }
            case TABLE -> {
                intermediate.createTable();
            }
            case 
        }
    }
    intermediate.createParagraph().createRun().addBreak(BreakType.PAGE);
    pos++;
}
XWPFTable tempTab = new XWPFTable(tbl, intermediate);
//
//Add items to tempTab here
//
intermediate.setTable(i,tempTab);

Answered By - Adnan
Answer Checked By - Candace Johnson (JavaFixing Volunteer)